Increased 1-year survival and discharge to independent living in overweight hip fracture patients

Figures & data

Table 1. Patient characteristics according to the 3 BMI groups

	BMI
	< 22	22–26	> 26	p-value
All patients, n (%)	364 (43)	341 (41)	138 (16)
Age, mean (SD)	83 (6)	81 (7)	80 (7)	see notes
Age, median	83	82	80
(range)	(66–99)	(66–100)	(66–97)
Women, n (%)	290 (80)	229 (67)	98 (71)	< 0.01
Fracture type, n (%)				0.05
Femoral neck	176 (48)	181 (53)	78 (56)
Trochanteric	163 (45)	138 (41)	44 (32)
Sub-trochanteric	25 (7)	22 (6)	16 (12)
Surgical procedure, n (%)				0.5
Cannulated screws	87 (24)	95 (28)	39 (28)
Plate or intramedullary nail	188 (52)	160 (47)	60 (44)
Total or hemiarthroplasty	89 (24)	86 (25)	39 (28)
ASA, n (%)a				1.0
1–2	159 (44)	148 (44)	60 (44)
3–4	200 (56)	192 (56)	77 (56)
No. of comorbidities, n (%)b				0.9
0	37 (10)	24 (7)	12 (9)
1	99 (28)	102 (30)	39 (27)
2	102 (28)	87 (26)	38 (28)
≥ 3	124 (34)	125 (37)	49 (36)
Katz ADL, n (%)c				0.5
A-B	330 (91)	318 (94)	129 (94)
C-G	31 (9)	22 (6)	9 (6)
Living alone, n (%)d
Yes	248 (71)	206 (63)	90 (65)	0.08
Walking aid, n (%)e				0.8
No aid or 1 stick	196 (60)	258 (64)	66 (59)
Frame or 2 sticks	128 (39)	141 (35)	44 (40)
Wheelchair	5 (1)	3 (1)	1 (1)
Survival at 1 year, n (%)	306 (84)	280 (82)	129 (94)	0.006^f
Living independently
at 1 year, n (%)	209 (72)	190 (73)	101 (88)	0.003^g
Reoperation during
study period, n (%)	29 (8)	35 (10)	11 (8)	0.2

BMI: body mass index; ASA, American Society of Anesthesiologists; ADL, activities of daily living.

^amissing data (n = 7).

^bmissing data (n = 3).

^cmissing data (n = 4).

^dmissing data (n = 25).

^emissing data (n = 1).

Group differences regarding age were tested using 1-way ANOVA. Post-hoc test with multiple comparison between groups showed significant mean age differences between the group with BMI < 22 and the groups with BMI 22–26 and BMI > 26 (p = 0.02 and p < 0.001, respectively), athough there was no significant mean age difference between the group with BMI 22–26 and the group with BMI > 26 (p = 0.06).

^f,gThe p-value represents a significant difference between the group with BMI > 26 and the 2 other groups, from chi-square test (2-sided).

Table 2. The association between BMI and 1-year survival, adjusted for ASA, age, and sex using multivariate logistic regression analysis

	Odds ratio (95% CI)	p-value
BMI 22–26a	0.9 (0.6–1.4)	0.6
BMI > 26a	2.6 (1.2–5.5)	0.01
ASA 1–2b	3.6 (2.2–5.7)	< 0.001
Agec	1.0 (0.9–1.0)	0.001
Sexd	1.5 (1.0–2.3)	0.07

^aBMI < 22 as reference value.

^bASA 3-4 as reference value.

^cAge as a continuous variable.

^dMen as reference.

Figure 1. 1-year mortality in different BMI groups. The number of patients who died (of the total number in each BMI group) is shown in each bar.

Table 3. The association between BMI and ability to live independently 1 year after hip fracture, adjusted for ASA score, shared housing, age, and sex using multivariate logistic regression analysis

	Odds ratio (95% CI)	p-value
BMI 22–26a	1.0 (0.7–1.5)	1.0
BMI > 26a	2.6 (1.4–5.0)	0.004
ASA 1–2b	1.6 (1.1–2.4)	0.01
Shared housingc	2.0 (1.3–3.2)	0.003
Aged	1.0 (0.9–1.0)	0.02
Sexe	1.3 (0.8–2.0)	0.3

^aBMI < 22 as reference value.

^bASA 3–4 as reference value.

^cLiving alone as reference.

^dAge as a continuous variable.

^eMen as reference